SPV: Fix an issue of ++/-- for dvec/dmat.
diff --git a/SPIRV/GlslangToSpv.cpp b/SPIRV/GlslangToSpv.cpp
index 26d2f4b..470ed25 100755
--- a/SPIRV/GlslangToSpv.cpp
+++ b/SPIRV/GlslangToSpv.cpp
@@ -1174,6 +1174,8 @@
             spv::Id one = 0;
             if (node->getBasicType() == glslang::EbtFloat)
                 one = builder.makeFloatConstant(1.0F);
+            else if (node->getBasicType() == glslang::EbtDouble)
+                one = builder.makeDoubleConstant(1.0);
             else if (node->getBasicType() == glslang::EbtInt64 || node->getBasicType() == glslang::EbtUint64)
                 one = builder.makeInt64Constant(1);
             else